Images: JPEG/JPG, PNG, and HEIC/HEIF. Multi-page PDFs are also supported, with no limit on page count; each individual image can be up to 50MB. When you upload a PDF, Leo asks how to read it: Pages (convert each page of the PDF into an image) or Images (extract every image embedded in the PDF separately) — if in doubt, choose Pages. If uploading from cloud storage (Dropbox, Google Drive), make sure files are fully downloaded to your device first — files that are only available online can fail to upload.
